X-ray computer tomography (CT) is used in the industrial sector for destruction-free and contact-less examination of components. X-ray computer tomography, for example, allows the detection of material defects and their characterization with regard to their type and position in the component. Moreover, there is a need on the part of the industry to geometrically measure the component by means of X-ray computer tomography, so the adherence to manufacturing tolerances, in particular in the case of concealed inner structures of the component, can be checked.
In known methods for the examination and geometric measurement of components, the component to be examined is irradiated with X-radiation in the form of a substantially two-dimensional fan beam with the component rotating once during the irradiation. Fan beam data of the irradiated, substantially two-dimensional layer of the component are measured by means of a single- or multi-line detector. The multi-line detectors used have a substantially smaller line number than column number, for example 16 lines to 1024 columns. The irradiated two-dimensional layer of the component can be precisely reconstructed from the fan beam data. A method of this type is known, for example, from EP 0 875 751 A1. The drawback in this method is that to obtain three-dimensional volume data of the component, a considerable expenditure of time is required as the component has to be detected layer by layer. Because of the time expenditure required this method is unsuitable for an industrial geometric measurement of components.